JPS6141734A - Manufacture of particle dispersion type composite material - Google Patents

Abstract

PURPOSE:To manufacture the titled material having no pore and superior heat resistance, by pouring molten metal for matrix from the bottom part of a vessel fed with preheated ceramic particles. CONSTITUTION:The vessel 22 fed with metal such as Al, Al alloy, Ni, Cr, Co alloy, steel, stainless steel of metal material to be matrix, is entered a high frequency furnace 20. Further, a partition chamber 23 fed with ceramic particles 28 such as Al2O3, SiC, ZnO2, TiC and having an opening hole 24 and a gas exhausting hole 25 at the bottom and upper parts respectively, is arranged therein, and a weight 26 is mounted thereon. Electricity is conducted to a coil 27 of the furnace 20 to preheat the particles 28 and melt metal in the vessel 22, molten metal is entered into the chamber 23 from the hole 24, inside gas is pushed out from the hole 25, and said metal is filled in the particles 28 and solidified. The titled material superior in heat shock resistance and composed of metal matrix in which ceramic particles are dispersed uniformly without pores, is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing a particle-dispersed composite material. More specifically, the present invention relates to a method for producing a composite material containing almost no bubbles, in which ceramic particles are uniformly dispersed in a metal matrix.

Conventional technology Conventionally, heat-resistant alloys, such as 30Cr-50Co-Fe heat-resistant alloys (
1MCo50), 27Cr-40Co-2ONi-F
E-based heat-resistant alloys and the like have been used, but metals naturally have their limits because they have drawbacks such as being susceptible to creep deformation. On the other hand, it is naturally possible to use ceramics as a substitute for heat-resistant alloys, but since ceramics have low II strength, there is a problem in putting ceramics into practical use.

Therefore, emphasis has been placed on the development of particle-dispersed composite materials for IJ socks, which take advantage of the respective advantages of ceramics and metals, and several composite materials and their manufacturing methods have already been developed.

For example, E. Nakata Metals, 1982, pp.
Nos. 19 to 22 disclose that various composite technologies such as molten metal forging, diffusion bonding, casting, extrusion, rolling, and vapor deposition can be applied to composite processing methods for metal composite materials. The molten metal forging method is explained in detail.

A method for producing a particle-dispersed composite material using this molten metal forging method will be explained with reference to the attached FIG. 2.

First, FIG. 2(a) shows an apparatus used in this method, which mainly consists of a mold 1 and a plunger 2, and a heater 3 is provided around the mold 1.

The mold 1 is filled with particles 4 to be dispersed, as shown in FIG. 2(b).
As shown in Figure 2, the particle 4 is brought into a backing state as dense as possible by pressurizing it with a pressure P1 using the single plunger 2.

Next, a steel wire mesh 5 is inserted into the mold 1 from above to prevent particles having a specific gravity smaller than that of the molten metal from floating during injection of the molten metal. In this state, the molten metal 6 forming the matrix is injected from above the mold 1 (see FIG. 2(C)),
Apply pressure (pi) again with plunger 2 (Fig. 2 (d)
(see) and cooling, the desired particle-dispersed composite material can be obtained.

However, when the metal as the matrix has a high melting point, the ceramic is subjected to thermal shock due to the casting of the molten metal, and as a result, the ceramic particles 10 are extremely susceptible to damage, as shown schematically in FIG. As a result, damage such as cracks 11 occurs. In addition, the formation of cavities (12 in FIG. 3) caused by gases such as air existing between and within the ceramic particles and gases generated during the casting process is also observed. This is thought to be due to the rapid injection of molten metal from above and the fact that during the cooling process during casting, solidification begins from areas that are easily cooled, such as the circumference and the surface. Therefore, to date, this type of composite material has not been commercialized with good quality.

Problems to be Solved by the Invention As described in detail above, in the conventional manufacturing method of particle-dispersed composite materials, molten metal was injected as a matrix from above the particles to be dispersed, which caused Since the gas inside the particles and the gas generated during the casting process of composite materials are difficult to escape, cavities may be formed in the final product.
Further, there was a risk that the dispersed particles would be damaged such as cracking due to thermal shock during casting.

Under these circumstances, solving the above-mentioned various problems and developing a method for producing high-quality particle-dispersed composite materials has become one of the important issues in this field.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a novel method for producing a particle-dispersed composite material, which can solve the various problems of the conventional methods. Another object of the present invention is to provide a high-quality particle-dispersed composite material obtained by this method.

Means for Solving the Problems In view of the above-mentioned current state of the conventional method for manufacturing particle-dispersed composite materials, the inventors have conducted various studies and researches in order to manufacture composite materials of good quality that can withstand use. It has been found that preheating the particles to be treated and carrying out the injection of molten metal from below is extremely effective for achieving the object of the present invention. The present invention was completed based on these findings.

That is, in the method for producing a particle-dispersed composite material of the present invention, a compartment having a partition wall having at least one opening and an upper wall having a gas vent hole is provided in the furnace, and charging ceramic particles and charging solid metal outside the compartment;
The method is characterized in that the solid metal is heated to melt and the molten metal is allowed to enter the compartment through the opening.

Although a high frequency furnace is most suitable as the furnace to be used, other heating furnaces may be used.

Operation FIG. 1 schematically shows, as a sectional view, an example of an apparatus for carrying out the method of the present invention. Below, according to this figure 1,
The method of the present invention will be explained in more detail.

The apparatus shown in FIG. 1 includes a high-frequency furnace 20, a container 22 for metal forming a matrix of composite material provided in the furnace 20 via a stamp material 21, and a partition for charging ceramic particles. It is mainly composed of a chamber 23.

The compartment 23 may have a bottom wall and may be open-bottomed and configured to be closed by the container 22. At least one and preferably a plurality of apertures 24 are provided in the lower side wall of the compartment 23 to allow molten metal to enter from the lower part of the compartment. Furthermore, the upper wall is also provided with at least one, preferably a plurality of gas venting holes 25, so that when molten metal enters from below, air contained between and within the particles is removed from above the compartment. It is configured to allow gases and any gases that may be produced upon contact of the particles with the molten metal to be vented to the atmosphere.

Further, a weight 26 is provided at the top of the compartment to prevent dispersion particles having a specific gravity smaller than that of the molten metal from floating up.

The shape of the compartment 23 is not particularly limited and can be appropriately selected depending on the desired shape of the composite material, and may be any shape such as a cube, rectangular parallelepiped, cylinder, or prism.

A heating means 27 (here, a high frequency coil) is embedded in the furnace wall of the high frequency furnace 20, which melts the solid metal for the matrix and preheats the dispersed particles in the compartment before the injection of molten metal starts. play a role.

To explain how to actually form a particle-dispersed composite material using the apparatus shown in FIG.
Particles 28 are charged inside. A solid metal 29 is then applied to form a matrix of composite material within the space of the container 22.
Pack it.

Here, as the dispersed particles, that is, the ceramic particles, for example, oxide ceramics such as Al2O3,3AIzOs.2SIO2, Zr0z, carbide ceramics such as SiC and TiC, sialon, etc. can be used. Also,
Composite material materials: AI, IJ Fuchs metals,
Examples include alloys thereof, N1, Co, Cr alloys, steel, stainless steel, etc. The ceramic material for the dispersed particles and the metal material for the matrix can be appropriately selected depending on the desired physical properties, intended use, etc. of the composite material as a final product.

Next, the high frequency coil of the high frequency furnace 20 is operated to perform high frequency heating, thereby preheating the ceramic particles 28 in the compartment 23 and melting the solid metal for the matrix packed in the container 23. In this way, the metal melted by high-frequency heating is forced into the opening 2 provided in the lower part of the side wall of the compartment 23 by its own weight and by pressurizing the liquid surface.
The molten metal gradually penetrates from below into the gaps between the ceramic particles through the holes 4 and 4. On the other hand, gases existing between and within ceramic particles, gases that may be generated due to contact between molten metal and ceramic particles, etc., are gradually pushed upwards into the compartment, and gas vent holes 25 provided in the upper wall soil are gradually pushed up. is discharged into the outside air through the

According to the method of the present invention, there is a good possibility that the gas present in the dispersed particles or between the dispersed particles is released to the outside through the holes 25 even during the preheating period, and also forms a matrix. Since the metal melt is injected from the bottom of the compartment, the gas removal efficiency is believed to be extremely high. Furthermore, by injecting the molten metal into the compartment 23 in a somewhat excessive amount and removing the excess molten metal from the gas vent hole 25, it is possible to further improve the gas venting efficiency and produce a higher quality composite material. .

After the above operation is completed, it is cooled to obtain a composite material in which the desired ceramic particles are dispersed.

EXAMPLES Hereinafter, the method of the present invention will be explained in more detail according to Examples. However, the present invention is not limited in any way by the following examples.

Using ceramic particles and metal having the compositions shown in Table 1 below, a ceramic particle-dispersed composite material was prototyped according to the above procedure.

Table 1 Metal properties of the sample materials (values are in %) Figure 4 (a) shows a partially enlarged cross section of these prototypes, and (b) shows a further enlarged view of that part. This is what is shown. As is clear from FIG. 4, the circular parts are the dispersed ceramic particles, and the other parts are the metal parts as a matrix.

The IJ Fuchs component is a heat-resistant alloy with a high melting point (melting point 1390°C) whose main component is CO, but even when cast using such a high melting point metal, there is no damage such as cracks to the ceramic particles. Not observed. Furthermore, as can be seen from the matrix, there are almost no cavities, indicating that the matrix metal almost completely fills the spaces between the ceramic particles.

For reference, by using the same material and injecting molten metal directly into the ceramic particles from above using the conventional method,
A composite material was prepared, but as schematically shown in Fig. 3,
Cracks were observed in the ceramic particles, and cavities were found to be formed due to residual gas.

Effects of the Invention Thus, as described in detail above, according to the method for producing a particle-dispersed composite material of the present invention, molten metal for forming a matrix is infiltrated from below the dispersed particles to prevent the melting of the matrix metal. Due to the characteristic of preheating the particles after charging the ceramic particles, it is possible to effectively avoid the formation of cavities in the composite product and reduce the dispersion of particles caused by thermal shock during molten metal injection. The problem of damage such as cracking is completely solved. Therefore, according to the present invention, it is possible to provide a high-quality particle-dispersed composite material that can be used satisfactorily, and its utility value can be said to be extremely large.

FIG. 1 is a schematic cross-sectional view of an apparatus for carrying out the method of the present invention, and FIG. 2 is a schematic diagram for explaining a method for manufacturing a particle-dispersed composite material by a conventional molten metal forging method. Figure 3 is a schematic diagram showing the cracking of dispersed particles due to heat is during conventional casting, and the formation of cavities due to gas existing within and between particles. , FIGS. 4(a): 16 and 4(b) are enlarged cross-sectional views of a part of the particle-dispersed composite material produced by the method of the present invention.

(Main reference numbers) 1-Mold, 2-Plunger, 3-Heater, 4-Dispersed particles, 5-Steel wire mesh, 6° Molten metal, 10 Ceramic particles, 11°
・Crack, 12...° cavity, 20" high frequency furnace, 21
Stamp material, 22° container, 23°/compartment,
゛24 hole/opening, 25...-gas vent hole,
26...-weight, 27...high frequency coil, 28...
Dispersed particles 29: Solid metal, 30: Ceramic particles, 31: Metal matrix

Claims (1)

[Claims] (1) A compartment having a partition wall with at least one opening in the lower part and an upper wall provided with a gas vent hole is provided in the melting furnace, and ceramic particles are charged into the compartment, A method for producing a particle-dispersed composite material, comprising placing a solid metal outside the compartment, heating it to melt the solid metal, and allowing the molten metal to infiltrate into the compartment through an opening in the compartment.